                    [:lbf :N]                  4.44822
                    [:m :ft]                   3.28084
                    [:kg :lb]                  2.20462262185
+                   [:hp :W]                   745.69987158227022
                    [:psi :kPa]                6.894757293168361
                    [:lb-per-gal :kg-per-m3]   119.826
                    ;; slurry rate conversion not needed (use [:bbl :m3])

                            :force                  [:lbf :N]
                            :length                 [:ft :m]
                            :mass                   [:lb :kg]
                            :pressure               [:psi :kPa]
                            :proppant-concentration [:lb-per-gal :lb/gal :kg-per-m3 :kg/m3]
                            :slurry-rate            [:bbl-per-min :bpm :m3-per-min :m3/min]

     (condp = force-unit
       :lbf [typical-force-lbf force-unit]
       :N   [((convert-units-f :lbf :N) typical-force-lbf) force-unit]))))

(defn typical-power
  ([] (typical-power (rand-power-unit)))
  ([power-unit]
   (let [typical-energy (first (typical-total-pump-energy :J))
         typical-power  (condp = power-unit
                          :W  typical-energy ;; Assume energy expended for 1 s
                          :hp ((convert-units-f :W :hp) (first (typical-power :W))))]
     [typical-power power-unit])))
